diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index 555c67d13..a95559554 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -352,7 +352,7 @@ class UsersController < ApplicationController
       homework = HomeworkCommon.new
       homework.name = params[:homework_common][:name]
       homework.description = params[:homework_common][:description]
-      homework.end_time = params[:homework_common][:end_time]
+      homework.end_time = params[:homework_common][:end_time] || Time.now
       homework.publish_time = Time.now
       homework.homework_type = 1
       homework.late_penalty = 2